|Single LED flash, steadily on
||This means your Goodman furnace has no signal coming from the thermostat and won't operate.
||You should check your thermostat for an improper setting or connection.
|Single LED flash, blinks on and off
||This means that your furnace has locked out due to too many ignition attempts.
||After one hour of lockout, your furnace will automatically reset itself.
|Two LED flashes
||This means that the draft blower isn't functioning properly, or your furnace has a short in the pressure switch circuit.
||You should either repair the short or replace the pressure switch.
|Three LED flashes
||This means your furnace has an open pressure switch circuit or the induced draft blower is operating when it shouldn't be.
||You should check the pressure switch hose for blocks or an improper connection. Otherwise, see if any loose wiring needs tightening.
|Four LED flashes
||This means your furnace has a primary open limit circuit.
||You should check and clean all the filters, tighten the wiring, and see if there are any blockages in the flue.
|Five LED flashes
||This means that your furnace senses a flame without a call for heat.
||You should check for a leaky or open gas valve or a lingering burner flame.
|Seven LED flashes
||This warns of a low flame sense microamp signal. This is the result of a coated flame sensor or a lazy flame due to poor gas pressure.
||Adjust the gas pressure according to the information available to you.
|Eight LED flashes
||This means your furnace has an igniter circuit problem due to a defective igniter or an improperly connected igniter.
||Replace the igniter or check the ground wiring for defects.
|Nine LED flashes
||This means that your furnace has a high-stage pressure switch that won't close during a high-stage-induced draft blower operation.
||Check your Goodman furnace for a pinched or blocked pressure switch hose.
|Continuous LED flashes
||This means that your furnace has a reversed polarity of 115 volts.
||You will have to correct the wiring polarity after reviewing the wiring diagram.